The present invention relates to a remote-controllable automatic diaphragm control device for use with a CCTV camera permitting the diaphragm control to be changed over between an automatic diaphragm control mode in which a desired diaphragm control is achieved by utilizing a video signal supplied from a television camera and a remote diaphragm control mode in which the diaphragm is electrically adjustable to a desired diaphragm position entirely regardless of said video signal from the television camera, in a simple manner.
As the diaphragm control device for CCTV camera which is claimed to be excellent in its responsibility reliability and economical efficiency, there has already been proposed such diaphragm control device adopting the servometer of movable magnet type of movable coil type. However, such device of prior art has been still disadvantageous in that, upon deenergization, a displacement of the diaphragm occurs due to a shock or a vibration and a mechanical countermeasure to avoid this displacement would result not only in a reduced degree of freedom for design concerning location and arrangement of the respective mechanical components but also in a poor remote control function of the device. It has also been proposed to provide the servometer with a position detector elements therein for electric remote control, but such an arrangement has been also disadvantageous in its poor manoeuvrability.